Mechanical lock for side shift excavator



Feb- 10, 1970 K. L. MAGEE MECHANICAL LOCK FOR SIDE S-HIFTEXCAVATR i f 2 Sheets-Sh'et 'v1v Filed Feb. l. 1968 gill! INVENTOR. KENAETI-l L. MMEE.

SE TTLE, BATCHELDER 8 CLTMAN.

ATT'YS,

Feb. 10, 1970 K. L. MAGEE 35494536 MECHANICAL Loox FOR SIDE' SHIFT ExcAvAToR Filed Feb. 1. 1968 v.2 shets-shet a FIG. 3

INVENTOR. KENNETH L. MAGEE.

SE TTLE, BATCHELDER 8 OLTMAN.

ATT'YS.

United States Patent O 3,494,636 MECHANICAL LOCK FOR SIDE SHIFT EXCAVATOR Kenneth L. Magee, Racine, Wis., assignor to I. Case Company, Racine, Wis., a corporation of Wisconsin Filed Feb. 1, 1968, Ser. No. 702,402 Int. Cl. B60d 7/00 U.S. Cl. 280-456 3 Claims ABSTRACT OF THE DISCLOSURE A mechanical locking mechanism for securing a side shiftable frame of an excavator on the fixed frame lin any one of an infinite number of positions. The mechanism includes shiftable pads which are reciprocated on the mobile frame and are forced into engagement with the fixed frame through manual control members thereby s ecuring the shiftable frame on the fixed frame. The individual manually operated members may be interconnected through a linkage system to be simultaneously actuated by a single manual control lever.

BACKGROUND OF THE INVENTION The present invention relates generally to a side shiftable excavator, such as a backhoe, and more particularly to improved apparatus for locking the side shiftable frame of the excavator on the fixed frame thereof.

For many years it has been common practice in the excavating art to mechanically lock the mobileframe of an excavator to an immobile frame in a plurality of predetermined positions relative to the immobile frame.

In more recent years it has been found desirable 'to be capable of locking the mobile frame in any one of an infinite num-ber of positions with respect to the fixed frame. In an effort to save time and eliminate the requirement of the operator to dismount the excavator for shifting the mobile frame on the fixed frame, it has recently been proposed to provide hydraulic locking means between the two frames which may be actuated by the operator while he is at the normal operating position of the excavator. Such a device is disclosed and claimed in Patent No. 3,304,100 issued to Elton B. Long and assigned to the assignee of the present application.

While the hydraulically actuated device has found considerable commercial success and yhas readily been accepted -by the majority of the industry, the limited finances available to some purchasers has dictated that a less expensive mechanism should be available in case the more complicated and expensive hydraulic locking means disclosed in the above mentioned patent is not economically feasible.

SUMMARY OF THE INVENTION The present invention provides a simple and efiicient mechanism for locking the movable frame of a side shiftable excavator on the fixed frame thereof in any one of an infinite number of positions. The present invention can readily =be incorporated in a conventional side shift back- -hoe of the type disclosed in the above mentioned patent with very minor modifications to thereby produce a device which is considerably less expensive than was heretofore known. Furthermore, the present invention ca n readily be modified to incorporate any one of three locking mechanisms with only minimal changes in structure of the entire device.

Generally speaking, the present invention incorporates the frame structure of the fixed and mobile frame of the side shift backhoe disclosed in the above mentioned patent and provides a simple and efficient manual lock for lock- 3,494,636 Patented Feb. 10, 1970 ing the shiftable frame on the fixed frame in any one of a number of positions.

Thus, the primary object of the present invention is to provide a simple and inexpensive mechanical mechanism for locking the mobile frame of a side shiftable excavator in any one of an infinite number of positions along the fixed frame of the backhoe.

Anther object of the inventoin is to provide a mechanical mechanism for a side shiftable excavator which can readily be incorporated in hydraulic locking devices heretofore known.

A further object is to provide an inexpensive remotely controlled mechanical locking device which will simultaneously actuate a plurality of locking members.

Other objects of this invention will appear in the followingdescription and appended claims reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

FIGURE 1 shows a perspective view of a tractor mounted side shiftable backhoe equipped with the mechanical locking mechanism'of the present invention;

FIGURE 2 is a vertical sectional view taken generally along lines 2 2 of FIGURE l; and

FIGURE 3 is a rear elevational view partially in section of a slightly modified embodiment of the locking mechanism shown in FIGURES 1 and 2.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to FIGURE 1 of the drawings, there is shown a perspective view of a tractor mounted backhoe, generally designated at 10, Iwhich comprises a tractor 12 having rubber tires 14, a steering wheel 16, a drivers seat 18 and a chassis 20. Of course, it is readily apparent that various types of tractors can 'be utilized in conjunction with the present invention and the tractors may ibe of the track-mounted type.

The backhoe assembly is attached to the rear end of the tractor and includes a stationary or fixed frame, generally designated at 22, integrally fastened to the tractor chassis in a suitable manner (not shown). The fixed or immobile frame comprises two generally horizontally extending beams 24 and 26, illustratively shown as being of a hollow rectangular cross sectional configuration, which are joined by welding or the like to the planar surfaces 28 of spaced vertically extending columns 30 and 32. The upper beam 24 is further supported by a pair of diagonally disposed braces 34 which are welded or otherwise secured to the surfaces 28 of the columns 30 and 32 and to the beam 24.

The rear. faces of the respective beams 24 and 26 carry vertically spaced plates 36 and 38, preferably of solid rectangular cross section. These plates constitute slide rails and are preferably welded or otherwise integrally secured to the rear faces of the beams 24 and 26. The slide rails 36 and 38 are vertically aligned with each other at different elevations and extend generally horizontally with the top slide rail 36 projecting above the beam 24 and the bottom slide rail 38 projecting below the beam 26.

Integrally attached to the lower beam 26 are three 'members including an angularly-shaped member 40', a horizontally disposed plate 42 and a vertically disposed plate 44. The three plates coact to define a bracket generally designated at 46. This bracket 46 supports the stabilizer or outrigger legs 48 by a pivotal connection between the downwardly extending portion of the angularly-shaped member 40 and the vertically exposed plate 44. l

A mobile frame 50 is slidably supported on the respective rails 36 and 38. For this purpose, the mobile frame is generally rectangular in outline and considerably smaller than the immobile frame 22. The mobile frame carries with it an operators seat 52 and a control panel 54 `and the backhoe assembly generally designated at 56. Since the backhoe assembly per se forms no part of the present invention, no detailed description appears necessary.

Structurally the mobile frame 50 comprises-a pair of vertically extending columns 58 and 60 integrally connected to a top plate 62 and to a bottom support plate 64. The top and bottom support plates 62 and 64 respectively have integral ears 66 and 68 which pivotally support a swing post 70. The swing post is hydraulically rotatable responsive to the actuation of a pair of swing cylinders, only one of which is illustrated in the figures, and is identified by the numeral 71.

The mobile frame is slidably carried on the immobile frame along the two slide rails 36 and 38. For this purpose, the upper horizontally disposed plate 62 has a stop or backup block 74 rigidly secured thereto which is adapted to have an abutment surface 76 forced into engagement with the first vertical surface 78 defined on the slide rail 36. The entire weight of the mobile frame 50 and its associated elements is supported on the upper surface 80 of the slide rail 36. A bottom stop block 82 is integrally secured to the columns 58 and 60 of the mobile frame and the stop 82 has an upper surface adapted to engage the lower surface 84 of the slide rail 36 to limit the` upward movement of the mobile frame on the fixed frame.

The lower end of the mobile frame 50 also supports a second backup stop member 88 providing a pressure bearing surface or abutment means 90 adapted to engage a vertical surface 92 defined on the rail 38.

Thus, the upper abutment and guide means 74 and 80 maintain the mobile frame on the fixed frame at all times while the lower abutment :means or surface 90 prevent any rotational movement counterclockwise as viewed in FIGURE 2.

The present invention provides a simple and efficient manner of locking the mobile frame on the fixed frame in any one of a plurality of positions. This is accomplished by utilizing the majority of components which define the hydraulic locking means in the above mentioned Patent No. 3,304,100. Thus, in the above mentioned patent, the hydraulic locking means includes cylinder assemblies 100 each comprising a cylinder 102 and a piston 104 reciprocated within the cylinder 102. Two such cylinder assemblies 100 are provided on each of the vertically extending columns 58 and 60 with the pistons 104 of the respective cylinders being in alignment with the respective rails 36 and 38. The free ends of the pistons 104 have bearing pads 106 defining pressure bearing surfaces 108 which are adapted to engage the surface on the respective rails 36 and 38.

In the actual construction of the cylinder assemblies in the commercial embodiment of the side shift backhoe disclosed in the above mentioned Long Patent, the cylinders are internally threaded :and adapted to receive cylinder caps connecting the hydraulic fluid conduit to the cylinder thereby allowing the pistons to be reciprocated by applying pressured fluid within the cylinder assembly.

According to the present invention, the locking means disclosed in the above mentioned Long Patent can readily be modified so as to provide a mechanical drive mechanism ,for reciprocating the pistons 104 within the cylinders 102. For this purpose, a sleeve 110 is threaded into each of the cylinders 102 with the inner surface defining a |thread having a rather large pitch. The internally threaded sleeve receives a correspondingly threaded screw 112 the free end of Which is in engagement with the piston 104 and has an integral head 114.

Thus, by mechanically rotating the screw, for example with a conventional wrench, the pistons carrying the pads 106 can be selectively forced into engagement with the vertical surfaces defined on the slide rails to securely lock the mobile frame on the fixed frazme. Of course, during this sliding movement of the piston on the frame within the cylinder 102 the respective abutment means 74 and 90 will be forced into engagement with the opposite vertical surfaceof the slide rails. Preferably a lock nut 116 is provided on each of the screws 112 to thereby securely lock the screw in a position corresponding to the lock position of the piston 104. Thus, it can readily be appreciated that through a simple modification, the hydraulic system disclosed in the :above mentioned Long Patent, can readily be modified to incorporate a mechanical lock for the mobile frame and the fixed frame.

This significant feature of the present invention is extremely important in the production of the mobile frames. Thus, the entire frame assembly can be constructed in an identical manner and the particular drive mechanism for pressuring the pistons within the cylinders, can be subsequently incorporated to suit the desires of a particular purchaser. By way of example, the entire assembly could :be constructed to include the less expensive locking mechanism in the form of a screw of the present invention and the hydraulic mechanism could be sold as an optional feature. This :optional feature could be provided on the assembly when it is being delivered to the purchaser or subsequently incorporated in the machine without any expensive modification-of the device.

Of course, any time it is desired to shift the mobile frame with respect to the fixed frame, all that is necessary is to rotate the respective screws 112 a sufficient amount to provide a small amount of clearance between the pads 106 and the respective surfaces of the rails 36 and 38. Thereafter, the entire mobile frame can be shifted on the fixed frame to any desired new position and the mobile frame can subsequently be locked in the new position in the manner described above. Preferably, stops 120 are provided adjacent each end of the respective rails 36 and 38 to prevent shifting of the mobile frame beyond the `outer ends of the fixed frame.

A slightly modified embodiment of the invention is disclosed in FIGURE 3. Since most of the parts disclosed in the embodiment of FIGURE 3 are identical to those shown in FIGURES 1 and 2, like reference numerals will be utilized to identify the various parts.

In the modified embodiment, linkage means are provided for simultaneously rotating each of the respective screws 112 through a member located remote from the respective screws 112 through a member located remote from the respective screws and preferably adjacent the operators compartment of the excavator. By way of example, the linkage means may be in the form of bell cranks respectively fixedly secured to each of the screws carried -by the upper cylinder assemblies 100. One leg of each of the bell cranks 130 are interconnected with each other through an adjustable link 132.

The opposite arms of the respective bell cranks are pivotally connected through adjustable links 134 to links fixedly secured to the lowermost screw heads 114.

Manual means are provided for actuating the linkage means simultaneously and thus actuating or driving the respective screws 'with respect to the cylinders 102. Again the manual drive means is only illustratively shown as including a lever pivoted intermediate its ends on a pin 142 supported on the control panel '54. The free end of the lever is pivotally secured through a connecting link 144 to the adjustable linkage 132.

In the position shown, all 0f the pistons 104 are in their extended position thereby locking the mobile frame on the fixed frame. Whenever it is desired to laterally shift the mobile frame, it is only necessary to rotate the lever 140 clockwise, as viewed in FIGURE 3, thereby rotating the respective screws 114 counterclockwise. It should be noted at this point that the pitch diameter of the threads on the respective sleeves 110 is such that only approximately one-fourth turn is required on each of the screws to move the free ends of the screws sufficiently allowing the pads and pistons to be retracted sufficiently to facilitate sliding movement of the mobile frame on the fixed frame. After the mobile frame has been repositioned, it is only necessary to again rotate the lever 140 counterclockwise to the position shown in FIG- URE 3 thereby simultaneously actuating all of the screws and locking the mobile frame ony the fixed frame. Preferably, stop means may be provided for maintaining the control lever 140 in the position corresponding to the locked position of the mobile frame. This may be accomplished by providing an aperture in the panel 54 which receives a pin 120 providing an abutment stop for the control lever.

Since the respective links 132 and 134 are adjustable in length, it is very simple to adjust the mechanism so as to insure that each of the pads will be in locking engagement with the respective rails upon appropriate movement of the manual control.

It is to be understood that the particular linkage and control mechanism are merely exemplary and various modifications could be made without depalting from the spirit of the invention. Thus, by way of example and not of limitation, the manual control lever 140 could readily tbe replaced with a foot control which could be spring biased to the released position and locked in a suitable manner to any position corresponding to the locked position of the respective screws 112.

While one exemplary embodiment of the invention has been described in detail, it `will be apparent to those skilled in the art that the disclosed embodiment may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting, and the true scope of the invention is that defined in the following claims.

I claim:

1. In an excavator having a side shiftable frame slideably carried by means of slide rails along at least upper and lower slide rails of a stationary frame, the improvement comprising means for mechanically locking the side shiftable `frame in any one of an infinite number of positions along the stationary frame, which locking means comprise a plurality of spaced screwed actuated pads, adapted when actuated to engage said slide rails and lock the side shiftable frame on the stationary frame, each of said pads being supported by a piston within a cylinder and adapted to be actuated by a screw, said screw having a threaded connection with said cylinder and having a free end in engagement with said piston, linkage means interconnecting each screw and a manually operable member connected to said linkage means remote from said screws whereby operation of said member simultaneously actuates all of said screws, so that the side shiftable frame may be rapidly relocated with respect to the stationary frame in any desired position merely by mechanical actuation without requiring the operator of the excavator device to leave his seat and dismount the excavator.

2. A side shiftable excavator as defined in claim 1 in which the side shiftable frame comprises a pair of vertically extending columns integrally connected to a top plate and a bottom plate and in which there are four spaced screw actuated pads separately located one each at substantially the upper and lower ends of each of the pair of vertically extending columns of the side shiftable frame, said pads being adapted to engage in pairs on said upper and lower slide rails.

3. A side shiftable excavator as defined in claim 1, further including removable sleeve means interposed between the respective cylinders and screws.

References Cited UNITED STATES PATENTS 2,278,254 3/ 1942 Enghauser 269-222 X 3,304,100 2/1967 Liong 214-138 X HUGO O. SCHULZ, Primary Examiner U.S. Cl. X.R. 214-138 

